The present invention relates to a golf club head and a golf club using the same.
An impact sound of the golf club head has been conventionally regarded as an important factor. Particularly, the quality of the impact sound is quite important for a golf club head including a hollow portion therein and a golf club head possessing a thin portion because these golf club heads are apt to produce a relatively great impact sound. The current trend is to reduce the thicknesses of individual parts of the head which is becoming larger and larger. Such a head tends to produce a low, loud impact sound, the tone quality of which is unpopular among many golfers.
In this connection, techniques for improving the impact sound have been disclosed. Specifically, Japanese Unexamined Patent Publication No. 93559/2003discloses a golf club head which is increased volume relative to the weight thereof by providing ribs on an inside surface of a sole, the ribs extending in a direction perpendicular to a face surface, thereby providing a good hit feeling and a comfortable impact sound at club-on-ball impact. Furthermore, Japanese Unexamined Patent Publication No. 313636/1995 proposes a technique pertaining to the sole provided with the rib, although the technique is not directed to the improvement of the impact sound. Disclosed in this patent publication is a hollow golf club head wherein a ridge is provided on an outside surface of the sole as extended perpendicularly to the face surface, the ridge contributing to the implementation of a low centroid design and facilitating swing through.
In terms of the volume and tone quality of the impact sound, the above golf club heads of the prior art are not fully improved. The vibrations of the sole upon impact with a ball are particularly great at an area near the face (an area adjacent to the face surface striking the ball). In the golf club heads of the above patent publications, the rib on the sole is extended from place near the face surface toward a back side of the head along a face-back direction. Therefore, the rib excessively suppresses the vibrations of the sole at the area near the face surface, so that the impact sound is excessively decreased in volume.
The above golf club heads of the prior art have another problem that the head tends to suffer decreased restitution performance because the portion near the face is excessively increased in rigidity because of the rib disposed adjacent to the face. An enhanced restitution performance for increasing carry distance may be achieved by decreasing the rigidity of the head. When decreased in the rigidity, however, the head will produce an impact sound excessively large in volume and low in tone pitch.
In a case where these ribs are not provided, on the other hand, the aforementioned problem of the impact sound having the excessively large volume or low tone pitch is likely to occur.